Apparatus for determining the speed and direction of movement of aircraft and of moving targets



` 356-150. 'XR 1942536 5R r Jan. 9', 19314.'4 A., CLEMENT: 15542535'v Afr-amiss -Fox nmmamius THE sxsn mm mgscnoxw vor' uovwsm of' AIRCRAFT am: or uovnze rneazrs Filed .my 29, 1950 2 shears-shan i A. 'CLEMENTI APPARATUS PQR DETERHINING THE SFEED AND DIRBQTIOH DF XDVEHENT OF AIRRAFT AND OP MOVING TARGETS 2 Snats-Shn-ltu Filed July 29 I/...625i i 11-., 11111 15.1 14.... v p.

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nmrso 's'ra'res' rar APPARATUS FOeDETERMrNING 'um SPEED AND nInEc'rIoN or MovnMsNr 0F AIRCRAFT No oF MOVING TARGETS Antonio iementi, Vienna, Aastra, assigner to Actiengeselscnaft C. P. Guen'. Optische Anstalt Actiova spoiecnost. K. P. Goerz opticky ustav, Pressburg, Bratislava, Czechoslovakia application suiv 29, 193e, serial No. 471,521, and in Germany August 10, 1929 l 1 Claim.

The present invention relates to an apparatus which on the one hand permits of rapidly and mechanically determining the speed and direction of movement of arcrafts necessary for msnoeuvrrg es weil es the speed and direction oi moreroent of the mod, by which the two quantities are influenced; and on the other hand permits of determining the angle of allowance for the movement of the target for launching torpedoes or other missiles against a moving target.

The apparatus embodying my invention 'romptses a sighting device which for a given height of aircraft above the ground or the surface of the sea permits of determining the horizontal end t horizontal angie of the axis of Ve to a. stationary auxiliary the elrcret re target on the ground or the surface of the seaor e. movable target et the beginnn and at the end of a definite measuring period, end further comprises a double triangle soiving device, the elements of which are provided with divisions of lengths and angies, and are adjusted in accordance with the data given by the sighting and pennit in 'turn the direct reading of the speed and di tion of movement to 'oe determined. y

Since in aix-crafts, more particularly in small eil-Creas, it is limpossible tov mount e, horizontal range finder of the usuai construction, apanorama oelescope is used according to the present invention for determining the horizontal distance of the sW-dliary target, which is adapted to rotate around a. vertical axis and is provided at its boliom end with an entering reflector adapted to turn about a horizontal axis. For measuring the vertical angle or" the sight litre to the' reet, e, water level located in the focus of the ein) ive or in that of the eye piece or a Irly suroendedsighting hair cross is mounted in the iosver part of the said telescope. For Iogsrizhmicaly muitipliwlng the trieonometrical tangent of this angie with the height of the aircraft a'oove the auxiliary target, the arrangement is such that on the one hand the rotation of the enlerng reflector is transmitted to a pair of coursier'. cams by a`toothed gearing with a. leverage ratio of 2 to 1. The roation of one of the said ceros, which is provided with a handle and a reading pointer, corresponds to the log tan of the angie of rotaron of the other cam. On

the other hemd a circular scale concentric to the caro and also rotatable by a. hmdle. preferably through the medium of e.' toothed gearing,v can-les a logarithmic scale of heights.

apparatus for determining the direction and An embodiment of the invention is shown byv way cf esempio in the annexed drawings. Fig. 1 illustra'tes the geometrica1 basis'of determining the direction and speed of the aircraft and of the Wind. Fig. 2 illustrates the geometrical basis 60 of determining the speed and direction of movements of a target moving in a straight horizontal line with uniform speed. for Jnding the quantities required for launching a. missile against the said target. Fig. 3 is a plan view of 85 a double triangle solving de Yice, Fig. 4 is a. side elevation, partly in section, of the optical sightdistance of a target from the aircraft iyine at a. known height .above the same. Fig. fia shows a. somewhat exaggerated detail of Fie. 4. Fig.

5 is u plan View partly in section of the sighting device with an apparatus for determining the angie required as ailorvance for the .iiovement of the target in launching missiles against the same.

Referring now to Fig. l, let F1 be the horizontal projection of the aircraft at the beginand F2 the same projection at the end of the Measuring period and '11 Ai and F2 m the 80 horizontal projection of the longitudinal axis of the aircraft, While F1 if: is the direction of night, end is inclined to the asis of the aircraft at an angie K due to the lateral wind. Z is e stationary auxiliary target on the ground or the sea which is coiled herein an auxiliary target, notl because it is a second target usedlin the present method, but because the aircraft does noty towards Lne serne. This so called auxwherein c; and e: ere the angles that the lines connecting the aircraft and the auxiliary target make with the vertical'. h, which equals A, F1F=F;F", being the constant linear height of g the aircraft above the level of the target A, the aircraft being assumed to .65' in a idorzoni'al l plene Furthermore 'die azimuths of the auxiliary target relatively to the axes EH Ai and 4 Fn A: ofthe aircraft are i and a: respectiveLv. I! as preferred the measuring period is T=1Q0 11C- seconds' and if un the axis of the aircrsrtthe distance Falli*through which the air craftuies in 10U seconds in' the absence of wind should be, taken as 100 times-.the speed of the aircraft,

then the distance A1F=cT is the distance4 'the actual speed of flight of the air craft.

The 'elements o, K, c, a, K being as above'the angle 'reti-veen the direction of night and the axis of the aircraft indispensable for the ma'.- noeuvre of the aircraft, may be determined by the double triangle solving device shown in Fig. 3 vint-hout the necessiti;7 of any calculation.. provided that the l'loriecntal distances FiZ and F22. are irnovm,v as .vell'as aaimuths ai 'and a2 of the auxiliary target at the beginning and at the end of themeasu'ring period. This double triangle solving device consists i'n part of a rule 24' representing the longitudinal 'axis of the aircraft and provided with a longitudinal scale representing the speed of the aircraft. To this rule is secured a journal pin F1, representing the horizcntal proiection oi the aircraft, and an angle scale 25 for the horizontal angles. A rule 26 provided with a longitudinal scale for the horizontal distances is pivoted on the journal pin Fi and may be locked in any position to which it is adjusted by a thumb nutl 25a. The rules 2S and 24 carry slides 27 and 30 respectively provided with an adjusting These slides may bc locked in any position to which they are adjusted by set screws 2T@ and 30a, respectively. To each of the two slides angle scales z8 and 3l and journal pins Z and A are respectively secured. On these journal pins ruies 29 and 32 are respectively 'pivotedthese roles ng provided. with longitudinal scales and adapted to be clamped against the angle scales above them by a thumb not 28a and 31a respectiifely. The rule 29, provided with a longitudinal scale for horizontal distances.- carries a slide 33 provided with an adjusting mark F2 and rneans for clamping the saine in position. On the pin 7:71 a further rule 34 is pivoted which is provided with a speed scale similar to that of the rule 32, and is adapted to be adjusted relative to the angie scale 25 independently o'f the rule 26 and to be claznpedin position by a screw 25h below the saine.

This device is used as follows: The slide 30 is adjusted on 'the rule 2e to indicate the speed of the aircraft and is there locked in position. Then the rule 26, the division edge of which passes through the centres of the journal pins F1 and Z, is adjusted to the angle e; on tnc angle some 25 and is locked in position. Next the slide 2T is adjusted to the horizontal distance F122 is locked in position, andthe rule 29, the divisiin edge of which passes through the centre of the journal pin Z, is adjusted on the scale 28 to the dierenoe of the two horizontal angles a2ai and is locked in this position.

Tnereater the slide 33 is adjusted to the measured horizontal distance Z F2, and then the division edge of the rule 34, as Well as of the raison' rule 32, may be placed on the marked pointv F2, whereby on the one hand the actual speed n of the air craft may be read on the rule 34 and the speed ofthe wind on the rule 32, at the same time the angles K and e are obtained.

' In orderto determine-the horizontal distances 1,942,586 .j FiZ and FzZ as Well as. the horizontal angles oi Y' I A the auxiliary target relative to the axis of the air craft, the height h of the latter above the level of the auxiliary target beingknown, a sightv lng device would be desirable, which indicates, in general, the horizontal distance F Z as the product of the said height and the trigonometric tangent of the angle 41 of the line of sight from the air` craft to the auxiliary target relative to the vertical by sighting vthis target, the multiplication being effected logarithmically as' in the case of an ordinary calculating rule. This apparatus consists, as shown'in Figs. 4 and 5, of a telescope casing 2 rotatable around a vertical axis X on' a base plate 1 maintained horizontal. The telescope casing is' providedY with a horizontal -angle scale 2a serving for reading the horizontal angles in, s: of the auxiliary target sighted by means of a pointer la provided on the base plate. In this 'telescope casing the entering reector 4 is rotatably mounted by means of horizontal trunnions 3'-3', which reflector reflects the pencils of light coming obliquely from below into the pentaprisin 5 which deects the rays of light ver' tically upward through the objective 6. The image of the target thus appears in the focal plane B of the objective 6. For enabling the axis of the objective 'to be maintained in the vertical a focus Water level is mounted in the focal plane B and serves at the same lectivo lens. 2 is the eye piece. Secured to the frame of the entering reflector is a spur Wheel .segment 9 meshing with another spur Wheel segment 11 on a shaft l0 parallel to the trunnions 3--3. The leverage ratio between the segments 9 and l1 is 2:1, Fast with the segment l is a cern 1.2 coupled in well known .nehmer with another cam l5 by two very thin steel strips 13, 14 located side by side and each wound round part of the periphery oi each cam, the tfno' serios being wound in opposite directions. This well known arrangement is shown in detail and somewhat exaggerated in Fig. ed; the steel strip l5.- runs from the point a. of cam l5 along its periphery to the point of Contact o of the cams l5 and 12 time as the coland thence along the periphery of the earn 12 to the point e thereof, the si'ee". strip 13 runs from the pointd of cam l5 along its periphery to the point of contact b o'the cams 15 and l2 and thence along the periphery of the earn 12 to the point c thereof. lius the seel strips 13, 14 being kept tight, whenever the cam i2.is turned in one direction, say clockwise. the cam l5 is turned in the opposite direction, namely anticlockwise, and vice versa. The circimerentiai srxe'edsof the tivo cams at their point of contact b are oi' course equal. The cam l5, 'th-. angleof rotation of whichlcorresponds to the logarithm of the tangent of the angle of rotation of the other carn 12, is fast on a .shaft 16 par- 'sion of the scale 1S is adjusted to the known height of the air crafta'oove the auxiliary target,

this height being indicated by me pointer' 2a. f

Then by turnii'nir the handle 17 the image of the auxiliary target appearing inthe eye piece is adjusted, so as to exactly coincide with the bubble in the focus water level 1, whereupon the horizontal distances FiZ and Fez of the auxiliary target et'the beginning and at the endI respectively of. the 'measuring period of' 10D seconds may be directly read on the logarithmic division on scale 19 by -means of the pointer 18 fast on the handle ll. yThe division on4 scale 19 is as stated, a. logarithmic one on which linear heights are indicated by the pointer 23 and hoi-izontal distances by the pointer 18. At the same time the horizontal angles a1 and a2 of the auxiliary target at the beginning and at the end. of the measuring period relatively to thelongitudinalaxis of the air craft are found by reading on the scale 2a by means of the pointer la, whereby all of the fourquantities are determined to which the double triangle solving device, shown in Fig. 3, must be acusted.

The apparatus shown in Figs. 3 to 5 may also be used for determining the angle of allowance for the movement of the target proper, when missiles of any kind have to be launched from the aircraft against the said target, for instance a ship moving in a straight line With constant speed, the speed of the aircraft and of the missile being known.

For this purpose in the first-place the speed u of the ship and the direction s or the movement of the aircraft relative to the direction of movement of the ship must ce determined, the ship moving in the measuring period. through the distance :22:52'. Hence in accordance with the geometrical method illustrated in Fig. 2 and by means of the sighting apparatus shown in Figs. 4 an 5, the horizontal distances F121 and F222, and angles el and e: of the target proper, are measured at the beginning and at the end of the measuring period, which is preterahly l@ seconds. These measurements are effected in the manner berein'oeore described.'

First these four data are used for adjusting the double triangle solving device in such Inanner that the rule 26 is adjusted relative to the rule 24, located in the direction of flight of the aircraft, at the angle m by Ineens of the angle scale 25. The rule 26 is their clamped in position, the adjusting mark of the slide 27 being adjusted to the horizontal distance F121 of the target proper. The rule 29 is then adjusted -t'o the angle r2-e1 on the angle scale 28 and locked in the adjusted position; the marl: of the slide 33 is adjusted to the horizontal distance F222 of the target proper. If now the rule 2e is applied against this slide mark, the distance FxFz read thereon is equal to the change of distance having tagen place in the measuring period T. It now the mariiof the slide 30 is adjusted to 100 times the speed of the aircraft and the rule 32 is also placed on the point F2 indicated by the marl: of the slide 33, the angle a of the direction of movement of the ship relative to the axis or' the aircraft can be read on the angln scale 3l vvcl'iile on the rule 32 the speed c of the ship multiplied by 1GO can be read.

But thereby alsothe most advantageous angle of allowance r (Fig. 2) for the increment of the snip is determined, which angle is required for the miile to hit the ship, since for a given speed w of the missile it is found u tan vr= w therefore la rule 35, Fig. 5 is secured to the ibase plate l of the optical sighting'apparstus, and provided with a speed scale, and is placed vhundred seconds, the aircraft is at the same showing in Fig. 4.. 1

in the direction" of the axis of the aircraft, and i! Y on this rule 35 a slide 36 is mounted whch'car- 1 ries a mark E and-a horizontal arm 37, perp'enf dieular to the rule 35 and provided with a speed scale, and if-iurthermore on the said arm 37 a slide 38 is niountedlwbich is provided with'a mark E1 and which can beclamped in position by a set s crevv 40, then the optical sighting apparatus may` be adjustedat once to the angle Ir by bringing the edge of the arm 39 on the horizontally rotatable casing 2 onto the point of the arm 3'? indicated by the mark Ex, the said vedge being in the vertical sighting pla-ne and passing through the axis x of 'rotation of' the cas ing 2, this a'iustinent occurring after the slide 36 on the rule 35 has been adjusted to the speed w of the missile or torpedo and the slide 38 on Y the arm 3'? has been adjusted to the speed u '4 and both slides have been locked in position. 40 is a set screw for locking in position the slide 38 on the rule 37. The arm 39 is fast on the casing 2 and is held in position by a set screw lb screwed into the casing l. Prior to a fresh sighting of the target proper by the sighting apparatus adjusted to the angle 1 of allowance 100 relatively to the axis of the aircraft, the direction of flight of the aircraft must be changed by the angle a lsliown in Fig. 2) in order to launchl the missile or torpedo at the moment when the target proper appears at Za, in order to int the same at Zi. As will be understood, the rule 3e :night be dispensed with, when the apparatus is used only for determining the angle f of allowance for launching missiles.

'in order that the operation of the device shown in Figs. e and 5, in conformance with the geometrical showing in Fig. 2, may be more readily understood, the following explanation is suhmitted at this time. it has to be borne in mind that the operation of the device taires place in the presence of a full calm, that is, that there is no Wind. In Fig. l it is assumed that the target is stationary, but that there is Wind, but, of course the saine ligure applies when the target has a movement of its own, but there is no Wind; the relative movements ci the target and the aircraft being the sarde in both cases. If, however, the target oves and there is wind, the problem cannot be solved by the method illustrated in Fig. 2.

At the beginning of the measuring time, which has been referred to previously as being lusually one hundred seconds, the aircraft will be at a. certain definite height, determined by thc altmeter or other suitable instruments, above the point El, shown in Fig. 2. The angle e. between the axis of the aircraft, represented in Fig. 2 by the line FiFs, and the line Zii, representing. the horizontal distance between the aircraft and the target at the time of beginning of measurements, can likewise be determined in the manner previously discussed with reference to Fig. l.

Now at the end of the measuring time of one he lit above the int -F2-, the ship havingv moved in the meantime to the position Zeso that the horizontal distance between the target and the aircraft is represented by Fuzzand the angle 2 between the axis of the aircraft and the line EeZ- can likewise ce determined in the manner indicated above with reference to the Il new, with the data obtained in the fore-., going manner, the two parsllelograms FiF'iZzZif and FiF-HAF: are drawn as shown in Fig. 2,'y it '-v will be readily seen that ZiZz (the 'distance the vessel.

This distance Z1Z2=F2A can be mechanically determined by the use of the double triangle solving device shown in Fig. 3, on which is set up the data corresponding to the irregular line F'zZzFzFzAFz. To carry out the desired calculations, the slide on the rule 24 is rst so adjusted that on the rule there may be read the distance 27T. equal to one hundred times the speci ned speed of the aircraft. Thereafter the rule 26 is tinned about an angle e; relative to the rule 24, at 'iifnich time the slide 27 of the rule 26 is adjusted to radicate thereon the distance of the target from the ship FiZi-:F'iZL the rule 29 is turned about the rule 26 so that between the tiro rules 26 and 29 an angle a2 minus ai. is enclosed. Thereafter the slide k33 on the rule 29 is a sied to indicate the distance of the tergeu iron ie aircraft FgZz ai; the termination o the time interval of measurements. The rule 32 is then rocked about its pivot point until its measuring edge comes adjacent the pointer mark the sl 33, so that there now may be directls7 yread on me rale 32 ine distance through which -lip has travelled during the rneasurin ti ne,

The angle a which may scale El. between the ules 'nich nas a complemen- 1 90. ihrougn which urse oi the aircraft -at such course will .vel of the target at righty'ning the speed of the' target, the es shown in Fig. 5, is ccr- This adjustment takes -'er. onl 2 after the rule 37 has aleen *Lianne-r with respect to rule 35 as nerecn the predetermined speed of 1 be launched from Athe aircraft. l\ e', assumine the aircraft to reach av point F3 as in Fig. ?A its course having been altered through the angle then when ille 'essel or target has in the meantime reached a.

position Z; such that the target is visible in the At this time 'angle -r of allowance ci' movement in the alongv tion of the sighting edge of the rule 39, then the projectile is released, and strikes the target at i the position Z4.- The rule 34. which is adjusted so that its edge coincides at a point with that point at which the rules 29 and 32 cross, indi'cates on its scale the relative speed of the softarget as compared to that oi the aircraft, i. e.

the vectorial difference of the speeds While the angle K between the rules 24 and 34. as measured ori the angle scale 25. indicates the angle of actual direction of travel or the longitudinal axis of the aircrat as compared to the apparent direc,- tion cI the movement of the target FrFi there being no Wind assumed. It is obvious that once my invention has been disclosed, numerous modications and adaptations will readily occur to those skilled in the art. Accordingly, it is intended that the invention be limited onlyby the scope of the appended claim.

What I claim is: In an apparatus for determining the speed and direction of movement of air-crafts and targets, an optical sighting device mounted the aircraft and comprising means for determining the hori zontal distances and the horizontal angles o a target below the level of the seid aircraft at the beginning and at the end of a predetermined measuring period, the said optical sighting apparatus being adapted to rotate around a vertical axis and comprising a casing, an entering reflector, means for turning said entering reflector around a horizontal axis, a earn journallcd in the seid casing, moans for turning :ne said cam at double the speed of the enteric reflector, a secont: cani journaled in the seid casing, means for actuating the second nie .ned cani ny the rst mentioned cam. Where anon the rst mentioned cam is turned thro. an angle c. the second mentioned cani is turned i .rough an angle represen ng the log tan c, a for enz. of the second mentioned carri to the said pointer, a scale for the said pointer, means for adjusting l'e said scale to the .logarithm of any given value of n, the height of the aircraft above the target., :hereby the said pointer shows directl7 on the scale the sum log har-log tan @zing (Il. ten el, a circular angle scale concentric with and feston the said casing, and a. stationary pointer. t' quantities thus determined serving for the adjustment of a socalled double triangle solving device for mechanically determining the said directions and speeds.

fisc' 

